Boiler



Nov. 17, 1931; j J. w. LOCKETT ET AL BOILER Filed Feb. 25. 1929 2 Sheets-{Sheet l Fig. I.

INVENTOR fo/m /14 [ac/re/f 5 aney fizchar ATTOR N EY Nov. 17, 1931. J. w. LOCKETT ET AL BOILER Fiied Feb. 25 1929 2 Sheets-Sheet 2 INVENTOR 170/20 /I. lac/ref) Syd ey er AT'II'ORNEY Patented'Nov. 17, 1931 STATES. PATENT OFFICE JOHN w. Locxarr Ann SYDNEY TUCKER, rrrzsrmaons BOILER coarranv, Inc, or oswneo, new

NEW YORK BOIL R Application filed February 25, 1929. Serial No. 342,524.

This invention relates to boilers, particularly the small or portable type of boiler such as intended for a variety of uses in buildings, plants and the like.

' It is one of the mainobjects of the invention to produce a boiler structure which is,

cheap, efficient and compact. One structure conveniently into cheap manufacturing units, .that is to say, into portions which in themselves may be easily and cheaply manufactured and handled concurrently by individualcrews, and which portions may be easily adjusted upon each other during final assembly.

A specific embodiment of thein'v ention in-' cludes improvements on a boiler type such as substantially disclosed in the copending application of Homer Addams, 1 Serial No. 119.817: Patent No. 1,703,084.

One feature provides areservoir to form a separate manufacturing unit, and a firebox portion to form a second manufacturing unit. The firebox may have spaced therefrom a surrounding wall to form the conventional water jacket. The reservoir may have openmgs or;

perforations to register with said water jacket when the drum is placed or embedded upon said firebox. The reservoir suitably takes the form of a recesseddrum to fit upon a rectangular firebox portion. 7

These and other features, capabilities and advantages of the invention will appear from thesubjoined detail description of one embodiment thereof illustrated in the accompanying drawings in which v Figure 1 shows a longitudinal section through the boiler 1 Fig. 2 is a section taken upon the line A-A of Fig. 1; 1

Fig. 3 is a similar section along the line B B of Fig. 1; i

Fig. 4 is a perspective showing the main portions or units of the boiler assembled; and

Fig. 5 illustrates in perspective the main units of the boiler as drawn apart.-

c The boiler consists of two princ pal manu facturing units, shown best in Fig. 5, the

, reservoir and the firebox portion v11.

The reservoirlOfisinLthe form of a recessed feature aims to subdivide the boiler drum and shown to include a main cylindrical shell portion 12, and for instance riveted thereto as at 13,'a semi-cylindrical front portion'including the curved sheet 1a. A 7

straight sheet 15, shown to be welded, forms the plane face of'said semi-cylindricalportion, andis suitably braced against boiler pressure by stay bolts'16 extending from said curved sheet 14. While the reservoir may i be all Welded or integral, therehas been shown, see Fig. 4, a longitudinal'seam of rivets 17 to take up. circumferential stresses.

The reservoiriis provided with a two-pass tube arrangement for the combustion gases, and includes-a lower tube nest 18 and an *.upper tube nest 19, all the tubes supported,

that is fastened, in suitable holes in a circular tube sheet 20 at the rear, and two semicircular tube sheets 21 and 22 respectively at the front, see'Fig. 1. Forpurposes presently to be explained, the reservoir at its lower side isprovided with an array of perforations '23 in thecylindrical shell portion 12,

or .oswiisro, NEwxoR-K, Assmnon's To YORK, a coerom'rron or and perforations 24in the said "plane sheet 7.

15. At 25 isindicateda steam outlet, at 26 a connection for the safety-valve,and at 27 amanholepwhile the numeral 28 indicates the connection for-a preferred feed water 1 supply at the rear lowerportion of the reservoir, and the numeral 29 a' drain conneca tion at the rear lower end of the firebox.

The firebox portion 11 is of rectangular cross section and built up of an inner wall 30 forming the firebox proper, and has spaced therefrom by a bottom portion 31 an outer wall 32, both walls thus providing the space for a water jacket surrounding thefirebox. The Walls are; suitably braced against each other by stay bolts 32' to resist boiler'pressure such as builds up in the water jacket when the boiler is in operation and due to the boiler communicating with the water jacket through the above mentioned perforations 23 and 24, as can be readily seen.

nwill. be seenthat by subdividing the ,boiler into separate manufacturing units, to

witf the reservoir or boiler drum and the firebox-portion, the shop efficiency is greatly ing the material.

increased so as to cheapen the product inasmuch as now the drum part, for instance, may be individually finished and handled 1n the so-called tubing and rolling department,

ing in that each portion and each connection is now freely accessible duringthe process of manufacture. This is particularly important for rolling the front ends of the lower tubes 18 into their tube sheet 22.

Inthedrawings is shown a suitable and preferred way of connecting the nrum portion 10 tothe firebox portion 11. The front portions of thewalls 30 and 32 are formed to extend straight upwardly soas to support, by their upper edges, the flat face of the semi-circular front portion of the reservoir, and so that the corresponding front portion of water jacket may find a straight connection with the water reservoir through the perforations 23. The rearcportions of the firebox are recessed or stepped down and shaped so as to conform to the curvature of the cylindrical portion of the drum which is to beimbedded thereon, said rear portions, furthermore, have inwardly bent upper edge portions 34: which thus may suitably join lengthwise the belly of the boiler drum, and. which maythus connect the water-jacket through the perforations 23 with the interior of the'dru'm. V

A smooth transition from the straight front portions to the inwardly bent rear portions at the corners 34? of the firebox, see F 5, may be produced by stretching or roll- While any suitable method of joining the boiler drum with the firebox portion may be chosen, it is simple, cheap, safe and particularly useful with small units to weld these two units together as shown. Occasionally it is diflicult to have the various edges of the firebox register properly with the corresponding edges or portions of the drum when welding. By providing alap weld joint at 34 accuracy may be largely ignored and the welding operation greatly faclhtated, as compared to a butt joint which would here require extreme accuracy to correspond with an adjacent butt joint'as at 85.7

The overlapping portion of this joint 34 then, rather embracing the front portion of the reservoir, as clearly seen in Fig. 4, will aid in locating-the boiler drum upon the firebox portion when assembling the same for welding. is

Not only does the cylindrical shape of the drum, as herein described, make for simplici- The sides of ty, compactness and for better utilization of the boiler material, that 1s, for greater durability thereof, but it also conduces to a certain much desired water circulation in the boiler, as will be shown. With the drum curving down into the firebox, ample firebox area is secured at a minimum height of the boiler structure. Furthermore, compactness and efficiency is obtained with the special tube arrangement in the boiler drum. The efficient cylindrical shape of the drum permits the elimination of certain stays which would otherwise be necessary. vDue to the absence of such stays in the lower portion of the boiler, the'lower pass or nest of tubes may have a compact tube arrangement, that is to say, a maximum of tubing per given drum area and such, as obtained by the staggered tube arrangement shown. It has the advantage of providing a maximum number of tubes crowded into the lower pass where the hot gases enter and intensely heat this particular portion of the drum area, that is, the lower front portion of the drum, to create the aforementioned efhcient water, circulation.

The lower tubes are shown to be preferably pitched from the rear down to the front, and partly so in order to clear the corner or joint 37 while providing a larger water space 38 at the bottom towards the rear of the drum, and also an opportunity for the provision of a hand hole 39 to be closed up by a cover 40, indicated in dot and dash. The pitched tube arrangement serves another purpose, that is, to cause the ater in the lower front corner of the drum to be intensely heated on account ofthe crowded tube arrangement in that corner. The gases after heating the lower outside of the drum enter the constricted upper area 41 of the firebox where they are caused to be drawn through the lower tubes into a return or fine chamber 42 which is formed in the rear of the drum between the tube sheet 20 and end cover 43. Thence the gases, having lost part of their heat, pass through the horizontal upper tubes, which may be less in number, into the flue .box it and off to waste, the course of the gases being indicated by arrows in Fig. 1.

Cold feed water enters the drum through the feed water connection 28 at the lower rear portion of the drum, draws through the relatively cold area of the said water space 38 which is left below the rear portion of the lower tubes, on towards the lower front corner of the drum, here to be intensely heated by high temperature gases outside and inside, thence to rise up into a zone of .cooler loo is enhanced or intermediate temperature, to circulate back again to the rear of the drum. It will thus be understood that the efficiency of such water circulation, as more fully described and explained in said copending application, through the preferred pitch of the lower tubes. It is particularly noted that with the improved construction, the circulation of the water passes not only toward the lower front corner of the drum but enters the water jacket at the rear end thereof and passes forwardly around the firebox and upwardly along the upper constricted portion 41 into theupper front end of the water reservoir and then backward along the upper row of flue pipes until it approaches the rear wall 20 and then down agaln past the water inlet 28. As a result, the greatest volume of water in the water jacket surrounding the firebox must flow toward the front end thereof before it is liberated into the cylindrical portion above the firebox.

It will further be seen that the simple shape of drum and firebox readily lends itself for the standardization of the product.

It is another feature of the present boiler design that the constricted portion 4:1 of the firebox may be reduced to a possible minimum by having the lower front portion of the drum extend a substantial distance into the firebox whereby the plane sheet 15, forming the top of the firebox portion 41, may be shorter than the lengthof the drum portion extending into the firebox which automatically reduces to a minimum the numberof stays 16 necessary to brace said plane sheet against boiler pressure. When thus the constricted area 41 is diminished, space may be gained to the rear of the firebox, that is, in the upwardly extending wing portions to either side of the cylindrical member or drum, see Fig. 3, so as to provide the necessary space required for adequate combustion and to provide the necessary heat transferring surface area.

It is obvious that various changes and modifications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claim.

We claim:

In a steam boiler, the combination with one manufacturing unit consisting of a cylindrical shell, of a closure member at its rear end, a rear tube sheet parallel to, spaced from said closure member and connected to said cylindrical shell, an arcuateextension at the upper front end of said shell, a lower segmental tube sheet parallel to said rear tube sheet and secured to the remaining front end of said cylindrical shell, an upper segmental tube sheet parallel to said rear tube sheet and secured to the front end of said extension, a crown sheet connected to the lower edge of the upper tube sheet, the upper edge of the than the upper lower tube sheet and the lateral edges of the extension between said upper and lower tube sheets, an upper nest of flue pipes extending from said upper tube sheet to the upper part of said rear tube sheet, a lower nest of flue pipes extending from said lower tube sheet to the lower part of said rear tube sheet, a second manufacturing unit consisting of an inner rectangular wall, an outer rectangular wall parallel to said inner rectangular wall to form a water jacket constituting a firebox wall, the rear portions of the upper edges of the lateral walls of said water jacket having right angular recesses and the upper edges of the rear walls of said water jacket being concave to register with the lower end of the extension of said first manufacturing unit and with the front end ofthe lower part of the cylindrical she-ll, the upper edges of the front portion of the inner wall being lower the outer wall whereby the location of the first manufacturing unit on the second manufacturing unit can be readily found and such front portion of the inner wall butt-welded to the extension of said first manufacturing unit and such front portion of the outer wall be lap-welded to said extension; and means for connecting the upper edges of the walls of said water jacket to the extension and lower part of the front portion of said shell, there being spaced openings in said shell and crown sheet to register with the space formed between the walls of said water jacket to facilitate the passage of water from said shell to said water jacket.

' JOHN W. LOCKETT.

SYDNEY TUCKER.

edges of the front portion of' 

